Electric-switch mechanism



May '27. 1924 Y c. DUNCAN ELECTRIC SWITCHv MECHANISM Original Filed Oct. 18,- 1919 27 f F/g Patented May 27, 1924.

UNITE-n; .affaires i. j 1,495,224 PATENTQEFICE. 'Y

` CHARLES DUNCAN, or MONTREAL, QUEBEC, CANADA.

ELECTRIC-SWITCH y MECHANISNL Original application.ledctob-er 18, 1919,Seria1 No. 331,711. 'PatentstmV 1,401,891,dated December 27, 1921. Divided and'ths application -led AOctober 18, 19'19. 'Serial I\1o.`331,710.v i

To all whom t may concern."

Beit known that I, CHARLES DUNCAN, a subject of the King of lGreat Britain, and resident of the city of Montreal, in the Province Yof Quebec and Dominion of Canada, have invented certain new and useful Improvements in Electric-Switch Mechanism, of which the following is a full, clear, and exact description. v Y j This invention relates to improvements in electric switches, and is a ldivision of the subject matter disclosed in Patent 1,401,891, granted to me on an application )filed December 27, 1921. v

The principal object of the present invention is to provide a switch of the tumbler typewhich may be manufactured and sold at a low cost and which will be durable and efiicient in operation. A

A further -object is to provide a switch so constructed that the cover maybe very easily applied and removed and will not become loosenedand rfall olf in use.l j

According yto the present invention the switch cover is secured to thebase by a crosspin mounted under spring tension. Cams are provided on the cover embracing the pin and holding the cover against Vaccidental disconnection therefrom.

In: the drawings which illustrate the inventionz- Fig. 1 is a vertical sectionalview of a tumbler switch constructed according to this invention.V

- 2 is a vertical, sectional view at right anglesto .Figure 1.

l Fig. 3 is atop'plan view of the switch.

Referring more particularly to the draw.- ings, 1f designates a porcelain base having a centrally disposed, rectangular aperture 12 formed therethrough, above which is a bridge 13 apertured at 14 for the passage of the switch-throw-lever.` Screw passages 15 are provided in the plane of'- oscillation of the throw leveras nearlr as possible to the periphery of the'base, so that the base is secured in a manner best calculated tojwithstand the stresses imposed by theoperation ofthe sw-itch. Conductor passages A16 are formed one at each side of the central aper.

ture 121 and entirely clearof` all working parts of the switch. Thesepassages are Yeach approximately equidistant 'between 'the passages 15. .Recesses 18are provided in the sides of the central aperture 12 to formA jour-` nals for theV circuitmakenand recesses 19 are formed 1n thesides of the slot 14 for the receptionof the switch lever pivot." A recess` 20 is formed around thel central aperture12 at the bottom ,of the base to receivefthefba'ckl cover.

The terminals21 and binding posts 22 are j secured together 'andtothe switch base by the usual screws-having their heads vlocated atthebottomof the-base so as to beinaccessible when theswitch is -in use. vThese screws are 'relieved of allY bending stresses by the embedding of thefte'rmin'als and bind# ing posts in the'porcelain baseand, therefore, have no Vtendency to'loosen'. Th'e'termina'ls arelocated at one end of the centrall aperture 12 as clearly seen in'Figur'efl. The circuit maker' 24 is a substantially,'U-shapedmember ofa size to Voscillate Vfreely in-the^recess 12 and tol enter 'forcibly between the f terlminals.A The extremities 25 of the armsfjof the circuitmaker are outwardly turned to project into-the recesses 18 where they' act as trunnions' supporting the circuit maker. The switch-throw 0*lever 26 occupies the slot -14 and projects at one end beyond thev base,

the end being threaded toreceive `a ball 27. The opposite end 'of the'lever is bifurcated and each vof theY bifurcations28 is connected throught an insulator 29 conveniently by,

hooking or clenchingthe `arms through vthe insulator. The'lever is supported by a vpin 30 which passes through it and rests vinthe recesses 19 of the bridge. A helical 'spring '31 is connected at oiie end to the'insulator between the bifurcations'28, and is connected at the opposite'end to the central part of material, and the base and bridgefare covered by a cover 33 having insulating lining-34.1

The pin 301sVY U-shaped so that its 'extremil ties 35 projectgabove the bridgew These-extremities 'are outwardly yturned so astoproy ject .beyond the pin i receiving recesses 19 of vrthe bridge.- The cover 33' is provided.' with a central aperture 36 at least large enough 'to permit the cover to bel rotated about the U-shaped pin. Diametrically opposite notches'37 are formed in the periphery of the opening 36 to enable the cover to be passed over the out-turned ends 35 of the pin. Bosses or cams 38 are arranged in pairs between the notches 37 and at diametrically opposite points at the edge of the aperture 36. The cams of each pair are spaced apart suiliciently to hold the out-turned pin ends 35 securely between them. In order to facilitate the rotation of the cover 33, necessary to attach and release-same and also to conceal the porcelain bridge exposed through the cover opening 36, the top of the bridge may be provided with a metal cap 39 having a centrally disposed crown portion l0 which ts freely within the coveropening 36 and forms .a central pivot about whichthe cover will turn easily. This capis provided with a centrally disposed cruciform opening 41 for the 'passage of thelever and pin30. The cap maybe attached to the bridge in any suitable manner which will hold it against Ylateralor rotary motionas by the provisionvof.down-turned simple;

lugs @engaging recesses or flattenedV portions of the bridge;l

Thegassembly otf' theswitch is extremely The circuit maker and switchthrowlever carrying'the insulator are connectedgby the spring 31 and dropped into place-from the back or bottom of thebase. The ball 274is then screwed ontofthe end of the lever to retain the parts and the lever drawn up until the pin 30 Ycanbe inserted.

yFigure 1.

sion holds the parts in this position. To ops The spring isinow slightlyin tension and holds the trunnions 25 oi the circ-uit maker in their recesses l and also holds the lever pin 30 in the recesses 19. The cover 33 is then dropped onto the baseaud rot-ated until the notches 37 pass the out-turned ends 35 of the pin 30. By the application or' slight force the roverm'ay now be rotated and the ends of the pin will ride up out of the notches 37 onto the cover and will rsubsequently ride up over and drop between the cams 38 so that the cover will be releasably held' against rotation,

The operation of the device is extremely simple. The tension of the spring applied to the unsupported end of the circuit maker vtcndsrto throw the circuit maker against one end'oiI the aperture 18 and at the same time inclines the lever until the lever and spring axes are in alignment, as clearly shown in TheV spring being in slight tenerate theswitch the leveris oscillated vin the V usual mannerfso that its lower end swings V YVpast the pivotal point of the circuit maker.

Inthis action the spring is slightly ten-- sioned untiljits point of' attachment to the .lever passes the pivotal point of the circuit l maken whereupon, it exerts a pull on. the

circuit maker to draw it to the opposite end of the aperture 12.

thereby, a cover apertured to permit its pastween ythe base and memberrwhereby it is The spring, in addition to..operating the. circuit maker, drawsr down on the lever and holds the extremities 35 of the pivot tightly against the cover 33. lt will benoted that these pin extremities 35 are out of parallel 76 with the cent-ral portion of the pin being turned toward the cover so that ,thev load of the spring bears only upon the cover'and the pin is supported Vclear of the cap 40 and the porcelain bridge. timesthe cover is tightly heldrand cannot be 4worked loose by vibration as frequently occurs with the ordinary screwed-on covers. It it is desired to remove the cover it is rota-ted to force the cams 38 under the pin extremities thereby elongating the'spring. After the cams are disengaged from the pin the cover is turned until the pin ends slip into the. notches Y37 whereupon, the .cover may be lifted ofl The total rotation Veither applying or removing the cover is only onequarter of a revolution so that the cover may be very quickly and easily removed, o1" applied. Y Y Y While vthe cover has been shown" in connection Ywith a particular base and particular switch construction it will beunderstood that neither off these areV essential to the operation of the cover as ithe sameV ei'ect will be produced by the use of a spring actuated pin which is not necessarily the pivot pin of the switch lever. Obvious.- ly, many changes iny the construction andV arrangement of parts may be resorted to without departing from the spirit of the invention or exceeding the scope of the claims, and, therefore, the claims may not be. construed as limited to the particulary mechanism vshown and described;

The advantages of the device are clearly defined andwill be readily apparent by any one skilled in the manufacture or installation of such apparatus but'for convenience the same are briefly enumerated. The spring is of such t-ypeand so arranged that maximum life thereby is ensured. The cover will not become loose and Vfall off exposing the live parts of the switch, nor will the coverY fastening become worn by use and inoperative. The cover maybe very easily and quickly removed or applied thus'simplifying the work of installation. Fewer assembling operations are required than in the manufacture of ordinary switches and these operations are extremely simple. .Y

`Having thus described my invention, what I claim is Y i l. In a switch they combination with abase, of a diametrically disposed member carried sage over said member inone position only,

vsaid cover being revoluble relatively to the base and member to occupy a position beheld tothe base.

The result is, that at all fi Y 2. The combination with a device according to claim 1, of a resilient connection extending between said member and the base.

3. In combination with a device according to claim l, a bearing for the cover carried by the base.

4. In combination with a device according to claim 1, a bearing for the cover carried by the base having a circular upstanding portion, the cover aperture being circular in part to receive said upstanding bearing portion.

5. In combination with a device according to claim 1, means on the cover engageable with said member to releasably hold the cover against revolution.

6. A device according4 to claim 1, in which the cover is provided with a recess to receive an end of said member, whereby the cover is releasably held against revolution.

7. In combination with a device according to claim 1, a. pair of cams on said cover defining between them a recess for the reception of an end of said member.

8. In a switch the combination with a base, of a crowned cap centrally disposed thereon, an elongated member above said cap disposed diametrically of the base and projecting beyond the crowned portion of the cap, and a cover having a central circular aperture for the passage of said crowned cap portion, and radial extensions of said aperture for the passage of said member, said cover being revoluble on the cap into engagement between Said member and the cap.

9. In combination with a device according to claim 8, cams arranged in pairs on said cover intermediate the radial aperture extensions thereof, the cams of each pair defining between them a recess for the reception of an end of said member whereby the cover is releasably held against revolution. y

10. A device according to claim 8, in which the cover is recessed to receive an end of said member, whereby thel cover is releasably held against revolution.

11. `A, device according to claim 8, in which the member is a U-shaped pin having its extremities outwardly turned to engage the cover and its centre U-shaped portion adapted to pass through the cover aperture.

12. In combination with a device according to claim 8, a spring arranged to draw said member and cover against the base.

13. In combination with a device according to claim 9, a spring arranged to draw said member and cover against the base and to releasably hold the member in engagementr between thek cams.

14. In combination with a device according to claim 10, a spring arranged to draw said member into the cover recess and to draw the member and cover' against the base.

15. In combination with a device according to claim 1, a switch operating lever pivoted on said member, and a switch operating spring connected to said lever and operating 0 draw said member and cover toward the ase.

16. A device according to claim 15, in which the cover is apertured for passage over said finger `in one position and is vrevoluble on the base for interposition between the base and finger.

1.7. In combination with a device according to claim 16, a cap for the base irrevolubly secured theretoforming a bearing for thencover and operating to hold said fingers agalnst revolution with the cover. t

18. A device according toV claim 16, in

which the base is recessed to receive a portion Lof said lingers and hold the same against revolution withthe cover. l

19. In a switch, the combination with a base, of a cover and a finger carried by the base and spring-pressed against the cover to releasablyV hold thecover to the base, said cover being recessed for the reception of said finger whereby the cover is releasably held againstrevolution.

20. In a switch, the combination of a base, a cover, a finger carried by the basel and spring pressed against the cover to hold the cover to the base, and a pair of projections on the cover defining a recess for the reception of said finger whereby the cover is releasably held against revolution.

21. lA device according to claim 15, in which the cover is interposably between the fingers and base by revolution and is provided with recesses for the reception of said fingers, whereby the cover is releasably held against revolution to dise'ngage it from between the lingers and base.

22.V A device according to claim 15, in which the cover is movable into engagement between the fingers and base by revolution, and cams arranged in pairs on said cove-r, the cams of each pair defining between them a recess for the reception of a finger.

In witness whereof, I have hereunto se4 my hand.

CHARLES DUNCAN. 

